Brown sulfur dye and process of making same.



UNITED STATES PATENT OFFICE.

GEORG LIST, OF OFFENBAGI-I-ON-THE-MAIN, GERMANY, ASSIGNGR "1'0CORPORATION OF CHEMISCHE FABRIK GRIESI-IEIM-ELEKTRON, FFRANKFORT-ON-THE-MAIN,

BROWN SULFUR DYE AND PROCESS OF MAKING SAME.

GERMANY.

960,652. Specification of Letters Patent.

No Drawing.

Patented June '7, 1910.

Application filed February 12, 1910. Serial No. 543,455.

To all whom it may concern:

Be it known that I, GnoRc LIsT, doctor of philosophy, chemist, a subjectof the German Emperor, and resident of Offenbach-on-the-Main, in theGrand Duchy of I'lessen, with post-office address Obermainstrasse N o.79, have invented new and useful Improvements in Brown Sulfur Dyes andProcesses of Making Same, of which the following is a specification.

I have found that new valuable dyestuffs result by heating thediphenylmethan derivative, obtained by condensation of orthonitrophenolwith formaldehyde (see German Letters Patent No. 7 2490), withalkalipolysulfids at temperatures exceeding 100 C. An addition of copperor its salts to' the mass being in reaction will be of great advantage.'The thus obtained new sulfur dyestuffs dye unmordanted cotton fromreddish-brown to violet-brown shades of very good fastness to light andmilling.

The following examples will serve to further illustrate the nature of myinvention and how it can be carried into practical effeet. The parts areweight.

110 C. and kept at this temperature for several hours until theformation of dye stuff is completed.

color acid the pasty raw mass is dissolved in water and the color acidprecipitated by passing a current of air through the solution. The thusobtained dyestuff dissolves in dilute alkalipolysulfids with violetcolor, in concentrated sulfuric acid with brown color and dyesunmordanted cotton elearreddish-brown shades with a violet bloom.

The raw pasty mass is dried and ground. To produce the free Example II:45 arts of the dinitrodioxydiphenylmethan, escribed in Example I, areadded while stirring to a boiling solution of 180 parts of crystallizedsodium sulfid 75 parts of sulfur and parts of water. As soon asthereaction, being 'very ener etic in the beginnin of -,the operation, sows down the mass is radually heated up to 150-180 C. and ally to190-210 for several hours until the color of a test portion does notincrease any more. The mass is dried and ground. The thus obtaineddyestuif dissolves in water, an addition of sodium sulfid not beingrequired. It is soluble in dilute alkalipolysulfids with violet color,in concentrated sulfuric acid with brown color and dyes unmordantedcotton reddislrbrown shades, somewhat more yellowish'ones as-thedyestufi, described in Example I, does.

Now what I claim and desire to secure by Letters Patent is thefollowin 1. The process of makin rown sulfur dyestuffs y heating theiphenylmethan derivative, obtained by condensation of orthonitro henolwith formaldehyde, with alkali oysulfids at temperatures exceeding 1002. As a new article of manufacture the brown sulfurdyestuffs which canbe obtained by heating the diphenylmethan de rivative, obtainable bycondensation of ortho-nitrophenol with formaldehyde, withalkalipolysulfids at temperatures exceeding 100 0., which dyestuffs dyeunmordanted cotton from reddishto violet-brown shades, and dissolve indilute alkalisulfids with violet color, in concentrated sulfuric acidwith brown color.

In testimony, that I claim the foregoing as my invention, I have signedmy name in presence of two Witnesses, this 31st day of January 1910.

(mono LIST.

Witnesses:

JEAN GRUND, CARL GRUND.

